Nanette Newman firmly established the brand, so much so that the original advertising slogan is well-remembered: 'Now hands that do dishes can be as soft as your face, with mild green Fairy Liquid'. Blue Peter, too, did its part - almost every week an empty washing up liquid bottle would be required during the construction part of the show. They never mentioned Fairy Liquid by name, of course, but if you wanted quality, that's what you'd use. (This was back when the bottles were simple cylinders, of course, and it seemed to take weeks and weeks of waiting to procure an empty bottle.)
Fairy Liquid is now produced by Procter and Gamble and remains a highly-recognised brand of washing up detergent in the UK. It's also available across Europe, although the names inevitably vary slightly in different countries. The fairy brand also extends to dishwashing detergent and a gentle, non-biological laundry detergent.
You can even get differently fragranced versions now, and there's the usual 2010 options of antibacterial, lemon, orange and other bizarre hybrids that make choosing washing up liquid like a visit to a cut-price gourmet restaurant. Do you really believe the lavender-and-octopus or the anti-bacterial-twine-and-magic-sausage varieties are really making any difference? In my day we had lemon or original and liked it... eucalyptus and garden mint extracts... tsk!